基于SSR分子标记的广西极小种群野生植物长叶苏铁遗传多样性分析

了解广西区内的国家一级重点保护植物长叶苏铁（Cycas dolichophylla K.D.Hill）的遗传多样性和变异特征对广西长叶苏铁的保护和管理有着重要意义。本研究利用筛选出的6对稳定性好的SSR引物对分别来自广西百色市田阳县梅茶镇（PL）、德保县那甲镇（NL）和德保县城关镇（QH）的3个长叶苏铁种群的遗传多样性和变异特征进行分析。结果表明：6对引物中，高度多态性引物（GZST055、GZST065、GZST088）和低度多态性引物（GZST002、GZST013、GZST019）各占50%。广西长叶苏铁3个种群的平均观测等位基因为2.833，平均有效等位基因为2.005，平均Shannon信息指数为0.657，平均观测杂合度为0.259，平均期望杂合度为0.359。群体的遗传分化系数为0.049，说明群体间遗传分化小，且群体内遗传变异占所有遗传变异的97%，3个种群的基因交流频繁且遗传背景相互混杂。总体来看，广西长叶苏铁遗传多样性水平较低，而德保县那甲镇（NL）种群的遗传多样性相对最高，应将该种群作为重点保护单元进行保护。本研究还对广西长叶苏铁资源保护工作提出了建议和对策。

Genetic Diversity Analysis of the Extremely Small Populations Wild Plant Cycas dolichophylla K.D.Hill in Guangxi Based on SSR Markers

Understanding the genetic diversity and variation characteristics of Cycas dolichophylla K.D.Hill, a national first-class key protected plant in Guangxi, is of great significance for the protection and management of C.dolichophylla K.D.Hill in Guangxi.In this study, six pairs of SSR primers with good stability were selected to analyze the genetic diversity and variation characteristics of three C.dolichophylla K.D.Hill populations from Meicha Town, Tianyang County (PL), Najia Town, Debao County (NL) and Chengguan Town, Debao County (QH) of Baise City in Guangxi.The results showed that among the six pairs of primers, highly polymorphic loci (GZST055, GZST065, GZST088) and low polymorphic loci (GZST002, GZST013, GZST019) accounted for 50% each.The average number of observed alleles was 2.833, the average number of effective allele was 2.005, the average Shannon''s information index was 0.657, the average observed heterozygosity was 0.259, and the average expected heterozygosity was 0.359.The genetic differentiation coefficient of the population is 0.049, which indicates that genetic differentiation among populations was small.The genetic variations within the population accounted for 97% of all genetic variation.The gene exchange of the three populations was frequent and the genetic background was mixed with each other.The genetic diversity level of C.dolichophylla K.D.Hill in Guangxi was low.The genetic diversity of the population in Najia Town, Debao County (NL) was the highest, so the population should be protected as a key protection unit.This article also puts forward some suggestions and countermeasures for the resource protection of C.dolichophylla K.D.Hill in Guangxi.